Pose estimation using CNNs on Point clouds
The answer is yes this is possible and here are the papers where they do almost exactly the same project you are describing above. Although none of the bellow combine gazebo, single point/single shot, 6D-pose and CNNs. In order to use synthetic data to train a model that works on real data.


Pose Estimation by Key Points Registration in Point Cloud
 (2019) By Weiyi ZHANG, Chenkun QI This paper uses gazebo to test validate the model they made.
Dex-Net 2.0: Deep Learning to Plan Robust Grasps with Synthetic Point Clouds and Analytic Grasp Metrics (2017) by Jeffrey Mahler, Jacky Liang, Sherdil Niyaz, Michael Laskey, Richard Doan, Xinyu Liu, Juan Aparicio Ojea, Ken Goldberg
Real-Time Seamless Single Shot 6D Object Pose Prediction (2018) by Bugra Tekin, Sudipta N. Sinha, Pascal Fua
This paper sounds like exactly what you want to do.
SSD-6D: Making RGB-Based 3D Detection and 6D Pose Estimation Great Again (2017) by Wadim Kehl, Fabian Manhardt, Federico Tombari, Slobodan Ilic, Nassir Navab 
This paper is also referenced by them.


The model will be able to be trained but how effect a model trained on the synthetic data will be able to properly function on real data will be the challenge.